Device for packaging products under controlled atmosphere

ABSTRACT

A filling and sealing device includes an upper part forming a bell and a lower part forming a bowl, receiving a container to be sealed with a film in the chamber defined by the two parts. The upper part has a wall, on the side supplying the sealing film, inserting and filling elements emerging inside the chamber between the sealing film and the lower edge of the wall for inserting products into the chamber and for filling the container therein. Preferably, the upper part also includes above the inserting and filling elements, a slot for passing through the sealing film, closing and locking elements with controlled actuation for closing the slot and lock the film relative to the upper part, and elements for introducing and/or removing fluid (gas).

BACKGROUND OF THE INVENTION

The present invention relates to a filling and sealing device for amachine for packaging products under a controlled atmosphere, moreparticularly food products, which may be solid, rigid or in pieces, incontainers such as trays, pots and similar packages, sealed with a film.

DESCRIPTION OF THE RELATED ART

The packaging of food and other products in such sealed packages iscarried out on machines called “sealers” or “thermoformer-sealers”,depending on whether the containers to be sealed are produced beforehandon another machine or are produced by thermoforming a thermoplasticsheet, for example, on the same machine as that on which the sealing iscarried out. It is often necessary, especially when packaging foodproducts, pharmaceutical products or other products that are perishableor pose problems, for the purpose of better preservation, protectionand/or hygiene, to carry out the sealing under a vacuum or in acontrolled atmosphere, an operation which involves removing air and/orinjecting (or reinjecting) gas.

A known and commonly used solution consists in removing the air and/orinjecting gas through holes made in the sides of the thermoforming film,along the drive systems. This solution does, admittedly, make itpossible to establish a well-controlled atmosphere in the packages, butentails a not insignificant loss of thermoforming film, the latterhaving to be of a substantially greater width than the containers to besealed, but does not allow the trays to be filled with products in thesealing station.

Other solutions proposed up until now for this purpose (see, forexample, documents U.S. Pat. No. 4,162,599, U.S. Pat. No. 4,624,099,U.S. Pat. No. 5,271,207, WO 96/09210) are complicated and expensive andyet are not entirely satisfactory. In particular, they do not make itpossible to produce, at the sealing station, satisfactory or reliablesealing of the chamber created around the container to be sealed,especially at the air-removal and/or purge-gas injection system, betweenthe sealing film and the container to be sealed, and especially do notallow trays to be filled directly in the sealing station.

In order to overcome the disadvantages concerning the insufficientsealing at the sealing station, document WO 99/17990 proposes a sealingdevice for a sealed-container packaging machine, which device, whilebeing of particularly simple and reliable structure, ensures perfectsealing of the chamber in which the welding of the sealing film to thecontainer takes place, thus making it possible to create, in the sealedcontainer, a better controlled atmosphere than was possible until nowand moreover allowing fluid products (for example liquid, pasty orpowdered products) to be introduced into the container inside thewelding or sealing station, before completely sealing the container.This sealing device, intended for a machine for packaging products undera controlled atmosphere in containers such as trays, pots and similarcontainers sealed with a film, comprises an upper part forming a belland provided with a welding head, and a lower part forming a pan. Thelower part receives at least one container to be sealed and interactswith the upper part so as to define, around the container to be sealed,a chamber in which continuous sealing film supplied beforehand over thecontainer is welded to the container by the welding head of the upperpart. The upper part comprises, in one lateral wall, on the side onwhich the sealing film is supplied, a through slot for the sealing film,controlled-actuation closing and locking means for closing off said slotand locking the film with respect to the upper part, means forintroducing and/or removing fluid (gas, air), and, where appropriate,filling means comprising spouts or orifices for introducing fluidproducts (liquid, semi-liquid, pasty or powdered products) that emergeinside the chamber between said slot and the lower edge of said wall.

No provision in made in document WO 99/17990 for filling the containerswith products other than fluids at the sealing station.

SUMMARY OF THE INVENTION

The subject of the present invention is a device for packaging productsin a controlled atmosphere that makes it possible, more particularly, tofill containers, inside the sealing station, with products that may evenhave a nonfluid consistency (rigid products, solid products, products inpieces, etc.), it being possible, and preferable, for these products tohave been placed under a modified or controlled atmosphere beforehand.

More particularly, the subject of the invention is a device for fillingand sealing such packaging containers, having all the advantages andcharacteristics of the device according to document WO 99/17990, andtherefore being complementary to this device but having a higher levelof performance and possessing a structure that is better suited to anindustrial packaging process and especially having the advantage ofallowing containers to be filled directly inside the sealing station, byvirtue of the possibility of introducing, into the chamber surroundingthe container to be filled and sealed, all types of products, of anykind, form, appearance and consistency but more particularly rigidproducts, solid products or products in pieces, if necessary placedunder a modified or controlled atmosphere beforehand, it being possiblefor these products to be, in particular, food products such as loins ofpork, poultry, fish such as processed or whole salmon, pates,vegetables, etc.

The advantages of these inserting and filling means are many, since theymake it possible, by virtue of introducing any products into thecontainers directly in the sealing station, to improve and ensureprotection of the food products and to considerably increase theirshelf-life and hygiene levels, since it is from now on possible for someof these products to be sent, transferred or conveyed directly from themanufacturing room into the sealing station of a packaging machine, orby way of metering equipment, thereby making it possible, by eliminatingall intermediate, external and environmental sources of contamination,to avoid clean rooms, laminar flow systems, etc., in the case of certainfragile products such as yogurts or certain delicatessen products,meats, fish, and vegetables that may or may not have been modified, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended schematic drawings, a more detaileddescription will be given hereinbelow of an illustrative and nonlimitingembodiment of a filling and sealing device according to the invention;in the drawings:

FIGS. 1 and 2 are schematic cross sections through a sealing deviceaccording to document WO 99/17990, and

FIGS. 3 and 4 are schematic cross sections through two embodiments of adevice according to the present invention, comprising, in addition tothe means already illustrated in FIGS. 1 and 2, means for filling thecontainer with products, for example rigid products, directly into thechamber surrounding the container at the sealing station.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

According to FIGS. 1 and 2, the sealing device (1) of a machine forpackaging products, in particular food products, in thermoformed traysintended to be sealed with a film (11), this device here forming part ofa thermoformer-sealer, comprises a lower part (2) in the form of a pan,intended to receive a tray (4) and fitted with a seal (18) on its upperedge, and with a stationary upper part (3) in the form of a bell,comprising a frame (8) secured to a support plate and surrounding amovable welding head (9) that serves to weld the film (11) to the rim ofthe tray (4).

The frame (8) of the upper part (3) of the welding device has a slot(13) running through its wall situated on the side on which the sealingfilm (11) is supplied, through which slot the film. (11) passes.Associated with the slot (13) is a controlled-actuation closing andlocking means (14) consisting, for example, of an inflatable rubber hosemounted in a hole (16) that emerges into the slot (13) such that, wheninflated, the hose (14) locks the sealing film (11) in the slot (13) andcloses off this slot in a completely sealed manner.

The frame (8) moreover comprises, in the same wall, between the slot(13) and the lower edge of this wall, one or more orifices or nozzles(17), for example for removing or injecting gas, emerging inside of thechamber (25) bounded between the two parts (1) and (2) or of the frame(8).

The device according to the present invention, and as illustrated byFIGS. 3 and 4, which assumes all the characteristics of the deviceaccording to FIGS. 1 and 2, comprises in addition to the orifices ornozzles (17), which, by virtue of their small size (cross section), areable to serve only for removing and/or injecting gas and/or introducingmore or less fluid products, at least one orifice or nozzle (17A) oflarger size (cross section) designed to allow the passage of allproducts and particularly of more substantial products, which may besolid, rigid or in pieces.

These larger orifices (17A), which may have varied cross sections andshapes according to the products that have to be able to be introducedthrough them into the tray (4) enclosed in the chamber (25) and mayconsist of all sorts of different materials, such as, inter alia,aluminum, stainless steel, plastic, etc., depending on the applicationsand the products to be packaged, may advantageously be supplemented, toallow the best transfer and care of the products toward the sealingstation (in the chamber 25), by manual or preferably automated insertingand filling means of the airlock type, in order to introduce theproducts (26) into the chamber (25) and deposit them in the tray (4)without adversely affecting the controlled atmosphere prevailing in thechamber (25). These inserting and filling means may in particularcomprise mobile transfer means (20), such as carriages in the form ofshuttles, mounted for example such that they may or may not be able totilt or pivot and so that they can move back and forth with an axialtranslational movement, under the action of cylinder activators orsimilar drive means, within guides (23), for example tubular guides,which may be provided with openings (24) for loading products into theshuttles (20) from outside the packaging machine. It should be notedthat in FIGS. 3 and 4 the guides (23) for the shuttles (20) maycomprise, in one or more locations, means (22) for setting a modified orcontrolled atmosphere that are independent and/or individual and/orcentralized, and the shuttles (20) in which the products (26) areadvantageously supported by means such as gratings may comprise seals(21) that provide perfect sealing of the shuttles within the guides,this making it possible for the products (26) to be introduced under aperfectly controlled atmosphere, through the orifices or nozzles (17A)into the chamber (25) and into the trays (4), without disturbing thecontrolled atmosphere already created in the chamber and thus in thetrays by virtue of the orifices or nozzles (17) for fluids.

The embodiment according to FIG. 3 shows an orifice (17A) made in theframe (8) on the same side as the slot (13) through which the film (11)passes, at a distance above the lower edge of the frame, thus betweensaid lower edge and the slot (13) through which the film (11) passes,and more precisely between said lower edge and the orifice or nozzle(17) for fluid.

In the embodiment according to FIG. 4, the orifice (17A) for introducingthe product to be packaged into the tray (4) is, by contrast, in theform of a cutout that is made in the lower edge of the frame (8). Thisorifice (17A) is therefore situated directly on the connecting portionbetween two successive trays (4) when the sealing device (1) is closedaround a tray (4) by the vertically movable lower part (2) being raisedagainst the stationary upper part (3).

It should be pointed out that in the embodiments according to theinvention, illustrated by FIGS. 3 and 4, the sealing device (1), or moreprecisely the frame (8) of the upper part (2), is higher than in thecase of the embodiment according to FIGS. 1 and 2, owing to the presenceof the orifice (17A) below the slot (13) through which the film (11)passes, this slot (13) thus also being situated higher (with respect tothe tray (4) to be sealed with the film (11)). For this reason, it maythus be wise, or even necessary, in certain instances to provide thesealing device (1) with means allowing an excess length of film (11) tobe advanced toward the inside of the chamber (25) through the slot (13),this excess length of film being taken up when the welding head (9)drops onto the tray (4) or similar container. This excess length of filmmay be advanced, for example, by mechanical, electrical, pneumatic ormotorized means, by pressure, suction, blowing air, etc.

1. A device for filling and sealing packages for a machine for packagingproducts under a controlled atmosphere in containers to be sealed with afilm; comprising: a stationary upper part forming a bell and providedwith a vertically movable welding head; a vertically movable lower partforming a pan, the lower part being adapted for receiving at least onecontainer to be sealed and interacting with the upper part so as todefine a chamber around the container to be sealed a chamber; an openingin the chamber, located above the container received inside the chamberfor introducing in said chamber a continuous sealing film, said filmbeing thereafter welded to the container by the welding head of theupper part; means for closing off said opening and locking the sealingfilm; means for establishing a controlled atmosphere inside the chamber;first inserting and filling means emerging inside the chamber below saidsealing film for introducing fluid products into said chamber forfilling the container received inside the chamber; second inserting and,filling means emerging inside the chamber below the first inserting andfilling means and having a larger cross section than a cross section ofsaid first inserting and filling means for introducing non-fluidproducts to be packaged into said chamber and for filling the containerreceived inside in said chamber, before welding of the sealing film tothe container; a guide means mounted into said second inserting andfilling means; means for setting a controlled atmosphere within saidguide means; and mobile transfer means mounted for reciprocaltranslation within said guide means and provided with supporting meansfor said non-fluid products that allows to introduce said products intothe chamber without disturbing the controlled atmosphere of the chamber.2. The device as claimed in claim 1, further comprising means foradvancing the sealing film in order to supply and accumulate an excesslength of sealing film in the chamber and to take up the excess lengthwhen the welding head drops onto the container to be sealed.
 3. Thedevice as claimed in claim 1, wherein the opening for supplying thesealing film into the chamber is a through slot made in the upper partat a distance above the lower edge of the upper part.
 4. The device asclaimed in claim 3, further comprising actuation-controlled closing andlocking means for closing off said slot and locking the film withrespect to the upper part.
 5. The device as claimed in claim 1, furthercomprising means for introducing or removing fluid that emerges into thechamber between the opening for supplying the sealing film and theinserting and filling means.
 6. The device as claimed in claim 1,wherein the mobile transfer means is able to pivot or tilt.
 7. Thedevice as claimed in claim 1, wherein said guide means comprises atleast one opening for loading the products into said mobile transfermeans.